Adjustable muffler



May 31, 1966 E. w. BOTTUM 3,253,676

ADJUSTABLE MUFFLER Original Filed Sept. 10, 1962 INVENTOR EDA/4K0 M borruM ML oN, SETTLE & CRQIG flrroz/wsfl United States Patent 3,253,676 ADJUSTABLE MUFFLER Edward W. Bottum, 9357 Spencer, Brighton, Mich. Original application Sept. 10, 1962, Ser. No. 222,411, now Patent No. 3,141,519, dated July 21, 1964. Divided and this application May 28, 1964, Ser. No. 370,841 3 Claims. (Cl. 181-64) The present application is a division of my copending application Serial No. 222,411, filed September 10, 1962, now Patent No. 3,141,519, issued July 21, 1964.

The present invention relates to an adjustable muffler, and more particularly to a mufller for use in reducing pulsations and noise in systems in which air or other gas flows, the muffler being adjustable to be effective in different systems.

The muflier of the present invention may be used in any system in which a gas must be exhausted, such as from the operation of a gasoline or other engine or in connection with the compressor of a refrigeration system. The muffler may be used on either the suction or discharge side. of a compressor or engine. However, the greatest effect from the muffler is normally achieved by installing it in the discharge line of a compressor or the exhaust line of an engine. The muffler is particularly useful in refrigeration systems where the elimination of noise is highly important.

The use of mufflers has, of course, been quite common in the past. However, the use of conventional prior art mufflers has to some extent been unsatisfactory in systems where high quality muffler performance is necessary. The configuration of the muffler is very important with reference to the performance of the muffler. The pressure drop and orifice conditions in the muffler can significantly affect muffler performance. Muffler performance is particularly important in refrigeration systerns where the pressure drop through the muffler and the amount of noise suppression in the muffler are very important. A muffler may perform satisfactorily with one refrigeration compressor at a given suction pressure or load condition. However, if the operating conditions of the compressor are changed, or if the muffler is utilized in a different system, resulting in a different pressure drop through the muffler, the performance of the muffler may be quite unsatisfactory.

It is, therefore, an object of the invention to provide an adjustable muffler.

Another object of the invention is to provide a muffler which, when installed in a system, may be adjusted to vary the orifice opening within the muffler with a consequent variation to the resistance to flow in the muffler.

A further object of the invention is to provide a muffler having a plurality of baffles and cooperating orifice openings which are adjustable externally of the muffler without the escape of gas from the system.

Other objects of this invention will appear in the following description and appended claims, reference being had to the accompanying drawing forming a part of this specification wherein like reference characters designate corresponding parts in the several views.

In the drawing:

FIGURE 1 is a side elevational view in section of one embodiment of an adjustable muffler according to the present invention; and

FIGURE 2 is a partial sectional view of the FIGURE 1 embodiment showing the muffler in an adjusted position.

Before explaining the present invention in detail, it is to be'understood that the invention is not limited in its application to the details of construction and arrangement of parts illustrated in the accompanying drawing, since the invention is capable of other embodiments and of being practiced or carried out in various ways. Also, it is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation.

Referring to the figures, it will be seen that the muffler 10 comprises a casing including a hollow cylindrical member 104 having end closures 14, 16 secured thereto. The closures 14, 16 may be secured to the member 104, as may be other components of the muffler, by any suitable method such as brazing.

The closures 14, 16 have openings 18, 20 in which are secured, respectively, inlet fitting 22 and outlet fitting 24. The inlet and outlet are suitably attached to conduits (not shown) in the system in which the muffler is used.

Secured within the member 104 are a plurality of spaced apart cup-shaped bafiled plates 100. Each baffle plate 100 is provided with a small opening 19 adjacent the lower portion of member 104 for the flow of oil through the muffler. Oil is, of course, present in the gases of a refrigeration system.

The baffle plates 100 form compartments 102 within the casing 104. A tube 106 extends through registering openings 108 in the bafiles. Gas flows into tube 106 from inlet compartment 110 and flows therefrom into outlet compartment 112. Annularly spaced openings 114 are provided in tube 106 in each compartment 102. Openings 114 permit the flow of gas into and out of the compartments 102 as the pressure of the input gas in the tube 106 varies to thus accomplish the mufliing function.

A second tube 116 is rotatably mounted within the tube 106. The tube 116 is provided at one end with a shaft element 107 which is connected thereto by a spider 109. The shaft-107 extends through a gas-tight fitting 111 to terminate exteriorly of the casing. The other end of tube 106 is also provided with a shaft element 120 which is connected thereto by means of a spider 122. The shaft element 120 is rotatably journaled in a plate 124. A cotter pin 126 is provided at the end of shaft element 120 to prevent withdrawal thereof. The plate '124 has an opening 128 which somewhat enlarges compartment 110 to permit additional expansion of gas. The

plate 124 also functions to support the inner end of in- I the openings 114, 118 are not in exact registry to thereby vary the size of the orifices formed by the openings and thus alter the muffler characteristics to suit different circumstances.

One of the important features of the invention is the double-seal arrangement provided between the shaft 107 and end closure 16. This sealing means effects a first gas-tight seal directly between the shaft and casing and a second seal between the shaft and easing by means of a cap which is provided over the external portion of the shaft.

Referring to FIGURE 1, it will be noted that the sealing member 111 is received in an opening 42 of. the end closure 16 and is secured thereto. The member 111 has an axial opening 44 therethrough which has a threaded portion 45 at the inner end thereof. The shaft 107 has a threaded portion 46 which is threadingly received by the portion 45 in the opening 44. As will be noted, a portion of the shaft extends exteriorly of the muffler and has a wrench engageable 48 for threading the shaft in Patented May 31, 1966 the member 111. A packing gland 50 is provided to seal the opening 44 against escape of gas from within the muffler. The gland 50 is conventional in structure, comprising a nut 52 which is threadingly received in threaded portion 53 of opening 44. An annular sealing element 54, fabricated from asbestos-graphite or the like, is positioned within opening 44 and is wedgedinto sealing engagement with the shaft 107 and angular wall portion 56 by the nut 52.

An internally threaded cap 58 is received on external threads 60 of the member 111. The cap 58 serves to further seal the muffier so that any gas which does escape via the sealing element 54 is further restricted from escaping from the system. The cap 58 is, of course, removed when it is desired to adjust the shaft 107.

Once the muffler of the present invention is installed, it may be quickly adjusted to the system to provide best performance. This eliminates the time and expense involved in installing different mufflers to achieve top performance. Additionally, the adjustable muffier provides an almost infinite range of adjustment which is not possible by using different mufilers of fixed characteristics.

Having thus described my invention, I claim:

1. An adjustable muffler for gases comprising a casing having an inlet and an outlet, a plurality of spaced apart baffies in the casing forming separate compartments, said baifies having registering openings therethrough, a first tube received in said registering openings and sealing said openings, said first tube having openings therein between each pair of baflles, a second tube rotatably received in the firsttube, said second tube having openings in annular alignment with the openings of the first tube and defining therewith orifices for passage of gases in either direction between said compartments and tubes, said first and second tubes being open ended, one end of said tubes receiving gases from the casing inlet and the other ends of the tubes discharging gases to the casing outlet, a shaft extending from a point exterior of the easing into connection with the second tube, sealing means effecting a gas-tight seal between the shaft and casing, a sealing cap over the external portion of the shaft to eifect an additional gas-tight seal, said shaft being rotatable by actuation thereof externally of the casing to move the openings of the second tube into and out of registry with the openings of the first tube to vary the orifice size defined thereby.

2. An adjustable muffler for gases comprising a casing having an inlet and an outlet, a plurality of spaced apart bafiles in the casing forming separate compartments, said baffies having registering openings therethrough, a first tube received in said registering openings and sealing said openings, said first tube having openings therein between each pair of baflles, a second tube rotatably received in the first tube, said second tube having openings in annular alignment with the openings of the first tube and defining therewith orifices for passage of gases in either direction between said compartments and tubes, said first and second tubes being open ended, one end of the said tubes receiving gases from the casing inlet and the other ends of said tubes discharging gases to the casing outlets, a shaft extending from a point exterior of the easing into connection with the second tube, sealing means effecting a gas-tight seal between the shaft and easing, said shaft being rotatable by actuation thereof externally of the casing to move the openings of the second tube into and out of registry with the openings of the first tube to vary the orifice size defined thereby.

3. An adjustable muffler as defined in claim 2 further characterized in that the axis of said shaft is coaxial with the axis of said second tube, a spider structure connecting said shaft to said second tube, said spider structure comprising a plurality of spaced apart radially extending arms to provide substantially unobstructed flow of gases thereby.

References Cited by the Examiner UNITED STATES PATENTS 1,821,688 '9/1931 Boume 181-57 X 1,833,518 11/1931 Ericson 18133 2,320,050 5/ 1943 Peterson 181--33 2,382,159 8/1945 Klemm 181-64 2,807,329 9/ 1957 Caldwell 181-55 3,141,519 7/1964 Bottum 181-57 3,145,800 8/1964 Marx 18164 FOREIGN PATENTS 334,717 9/1930 Great Britain. 550,868 1/ 1943 Great Britain.

57,235 1 0/ 1936 Norway.

LEO SMILOW, Primary Examiner.

R. S. WARD, Assistant Examiner. 

1. AN ADJUSTABLE MUFFLER FOR GASES COMPRISING A CASING HAVING AN INLET AND AN OUTLET, A PLURALITY OF SPACED APART BAFFLES IN THE CASING FORMING SEPARATE COMPARTMENTS, SAID BAFFLES HAVING REGISTERING OPENINGS THERETHROUGH, A FIRST TUBE RECEIVED IN SAID REGISTERING OPENINGS AND SEALING SAID OPENINGS, SAID FIRST TUBE HAVING OPENINGS THEREIN BETWEEN EACH PAIR OF BAFFLES, A SECOND TUBE ROTATABLY RECEIVED IN THE FIRST TUBE, SAID SECOND TUBE HAVING OPENINGS IN ANNULAR ALIGNMENT WITH THE OPENINGS OF THE FIRST TUBE AND DEFINING THEREWITH ORIFICES FOR PASSAGE OF GASES IN EITHER DIRECTION BETWEEN SAID COMPARTMENTS AND TUBES, SAID FIRST AND SECOND TUBES BEING OPEN ENDED, ONE END OF SAID TUBES RECEIVING GASES FROM THE CASING INLET AND THE OTHER ENDS OF THE TUBES DISCHARGING GASES TO THE CASING OUTLET, A SHAFT EXTENDING FROM A POINT EXTERIOR OF THE CASING INTO CONNECTION WITH THE SECOND TUBE, SEALING MEANS EFFECTING A GAS-TIGHT SEAL BETWEEN THE SHAFT AND CASING, A SEALING CAP OVER THE EXTERNAL PORTION OF THE SHAFT TO EFFECT AN ADDITIONAL GAS-TIGHT SEAL, SAID SHAFT BEING ROTATABLE BY ACTUATION THEREOF EXTERNALLY OF THE CASING TO MOVE THE OPENINGS OF THE SECOND TUBE INTO AND OUT OF REGISTRY WITH THE OPENINGS OF THE FIRST TUBE TO VARY THE ORIFICE SIZE DEFINED THEREBY. 